diff --git a/samples/weather-stdio-server/.gitignore b/samples/weather-stdio-server/.gitignore new file mode 100644 index 0000000..108d567 --- /dev/null +++ b/samples/weather-stdio-server/.gitignore @@ -0,0 +1,42 @@ +.gradle +build/ +!gradle/wrapper/gradle-wrapper.jar +!**/src/main/**/build/ +!**/src/test/**/build/ + +### IntelliJ IDEA ### +.idea/ +*.iws +*.iml +*.ipr +out/ +!**/src/main/**/out/ +!**/src/test/**/out/ + +### Kotlin ### +.kotlin + +### Eclipse ### +.apt_generated +.classpath +.factorypath +.project +.settings +.springBeans +.sts4-cache +bin/ +!**/src/main/**/bin/ +!**/src/test/**/bin/ + +### NetBeans ### +/nbproject/private/ +/nbbuild/ +/dist/ +/nbdist/ +/.nb-gradle/ + +### VS Code ### +.vscode/ + +### Mac OS ### +.DS_Store \ No newline at end of file diff --git a/samples/weather-stdio-server/README.md b/samples/weather-stdio-server/README.md new file mode 100644 index 0000000..d1edd7f --- /dev/null +++ b/samples/weather-stdio-server/README.md @@ -0,0 +1,140 @@ +# Kotlin MCP Weather STDIO Server + +This project demonstrates how to build a Model Context Protocol (MCP) server in Kotlin that provides weather-related +tools by consuming the National Weather Service (weather.gov) API. The server uses STDIO as the transport layer and +leverages the Kotlin MCP SDK to expose weather forecast and alert tools. + +For more information about the MCP SDK and protocol, please refer to +the [MCP documentation](https://modelcontextprotocol.io/introduction). + +## Prerequisites + +- Java 17 or later +- Gradle (or the Gradle wrapper provided with the project) +- Basic understanding of MCP concepts +- Basic understanding of Kotlin and Kotlin ecosystems (sush as kotlinx-serialization, coroutines, ktor) + +## MCP Weather Server + +The project provides: + +- A lightweight MCP server built with Kotlin. +- STDIO transport layer implementation for server-client communication. +- Two weather tools: + - **Weather Forecast Tool** — returns details such as temperature, wind information, and a detailed forecast for a + given latitude/longitude. + - **Weather Alerts Tool** — returns active weather alerts for a given US state. + +## Building and running + +Use the Gradle wrapper to build the application. In a terminal run: + +```shell +./gradlew clean build -x test +``` + +To run the server: + +```shell +java -jar build/libs/.jar +``` + +> [!NOTE] +> The server uses STDIO transport, so it is typically launched in an environment where the client connects via standard +> input/output. + +## Tool Implementation + +The project registers two MCP tools using the Kotlin MCP SDK. Below is an overview of the core tool implementations: + +### 1. Weather Forecast Tool + +This tool fetches the weather forecast for a specific latitude and longitude using the `weather.gov` API. + +Example tool registration in Kotlin: + +```kotlin +server.addTool( + name = "get_forecast", + description = """ + Get weather forecast for a specific latitude/longitude + """.trimIndent(), + inputSchema = Tool.Input( + properties = JsonObject( + mapOf( + "latitude" to JsonObject(mapOf("type" to JsonPrimitive("number"))), + "longitude" to JsonObject(mapOf("type" to JsonPrimitive("number"))), + ) + ), + required = listOf("latitude", "longitude") + ) +) { request -> + // Implementation tool +} +``` + +### 2. Weather Alerts Tool + +This tool retrieves active weather alerts for a US state. + +Example tool registration in Kotlin: + +```kotlin +server.addTool( + name = "get_alerts", + description = """ + Get weather alerts for a US state. Input is Two-letter US state code (e.g. CA, NY) + """.trimIndent(), + inputSchema = Tool.Input( + properties = JsonObject( + mapOf( + "state" to JsonObject( + mapOf( + "type" to JsonPrimitive("string"), + "description" to JsonPrimitive("Two-letter US state code (e.g. CA, NY)") + ) + ), + ) + ), + required = listOf("state") + ) +) { request -> + // Implementation tool +} +``` + +## Client Integration + +### Kotlin Client Example + +Since the server uses STDIO for transport, the client typically connects via standard input/output streams. A sample +client implementation can be found in the tests, demonstrating how to send tool requests and process responses. + +### Claude for Desktop + +To integrate with Claude Desktop, add the following configuration to your Claude Desktop settings: + +```json +{ + "mcpServers": { + "weather": { + "command": "java", + "args": [ + "-jar", + "/absolute/path/to/.jar" + ] + } + } +} +``` + +> [!NOTE] +> Replace `/absolute/path/to/.jar` with the actual absolute path to your built jar file. + +## Additional Resources + +- [MCP Specification](https://spec.modelcontextprotocol.io/) +- [Kotlin MCP SDK](https://github.com/modelcontextprotocol/kotlin-sdk) +- [Ktor Client Documentation](https://ktor.io/docs/welcome.html) +- [Kotlinx Serialization](https://kotlinlang.org/docs/serialization.html) + diff --git a/samples/weather-stdio-server/build.gradle.kts b/samples/weather-stdio-server/build.gradle.kts new file mode 100644 index 0000000..71fb297 --- /dev/null +++ b/samples/weather-stdio-server/build.gradle.kts @@ -0,0 +1,35 @@ +plugins { + kotlin("jvm") version "2.1.10" + kotlin("plugin.serialization") version "2.1.10" + id("com.github.johnrengelman.shadow") version "8.1.1" + application +} + +application { + mainClass.set("io.modelcontextprotocol.sample.server.MainKt") +} + + +group = "org.example" +version = "0.1.0" + +val mcpVersion = "0.3.0" +val slf4jVersion = "2.0.9" +val ktorVersion = "3.1.1" + +dependencies { + implementation("io.modelcontextprotocol:kotlin-sdk:$mcpVersion") + implementation("org.slf4j:slf4j-nop:$slf4jVersion") + implementation("io.ktor:ktor-client-content-negotiation:$ktorVersion") + implementation("io.ktor:ktor-serialization-kotlinx-json:$ktorVersion") + testImplementation(kotlin("test")) + testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.10.1") +} + +tasks.test { + useJUnitPlatform() +} + +kotlin { + jvmToolchain(17) +} diff --git a/samples/weather-stdio-server/gradle.properties b/samples/weather-stdio-server/gradle.properties new file mode 100644 index 0000000..7fc6f1f --- /dev/null +++ b/samples/weather-stdio-server/gradle.properties @@ -0,0 +1 @@ +kotlin.code.style=official diff --git a/samples/weather-stdio-server/gradle/wrapper/gradle-wrapper.jar b/samples/weather-stdio-server/gradle/wrapper/gradle-wrapper.jar new file mode 100644 index 0000000..9bbc975 Binary files /dev/null and b/samples/weather-stdio-server/gradle/wrapper/gradle-wrapper.jar differ diff --git a/samples/weather-stdio-server/gradle/wrapper/gradle-wrapper.properties b/samples/weather-stdio-server/gradle/wrapper/gradle-wrapper.properties new file mode 100644 index 0000000..37f853b --- /dev/null +++ b/samples/weather-stdio-server/gradle/wrapper/gradle-wrapper.properties @@ -0,0 +1,7 @@ +distributionBase=GRADLE_USER_HOME +distributionPath=wrapper/dists +distributionUrl=https\://services.gradle.org/distributions/gradle-8.13-bin.zip +networkTimeout=10000 +validateDistributionUrl=true +zipStoreBase=GRADLE_USER_HOME +zipStorePath=wrapper/dists diff --git a/samples/weather-stdio-server/gradlew b/samples/weather-stdio-server/gradlew new file mode 100755 index 0000000..faf9300 --- /dev/null +++ b/samples/weather-stdio-server/gradlew @@ -0,0 +1,251 @@ +#!/bin/sh + +# +# Copyright © 2015-2021 the original authors. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# https://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# +# SPDX-License-Identifier: Apache-2.0 +# + +############################################################################## +# +# Gradle start up script for POSIX generated by Gradle. +# +# Important for running: +# +# (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is +# noncompliant, but you have some other compliant shell such as ksh or +# bash, then to run this script, type that shell name before the whole +# command line, like: +# +# ksh Gradle +# +# Busybox and similar reduced shells will NOT work, because this script +# requires all of these POSIX shell features: +# * functions; +# * expansions «$var», «${var}», «${var:-default}», «${var+SET}», +# «${var#prefix}», «${var%suffix}», and «$( cmd )»; +# * compound commands having a testable exit status, especially «case»; +# * various built-in commands including «command», «set», and «ulimit». +# +# Important for patching: +# +# (2) This script targets any POSIX shell, so it avoids extensions provided +# by Bash, Ksh, etc; in particular arrays are avoided. +# +# The "traditional" practice of packing multiple parameters into a +# space-separated string is a well documented source of bugs and security +# problems, so this is (mostly) avoided, by progressively accumulating +# options in "$@", and eventually passing that to Java. +# +# Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS, +# and GRADLE_OPTS) rely on word-splitting, this is performed explicitly; +# see the in-line comments for details. +# +# There are tweaks for specific operating systems such as AIX, CygWin, +# Darwin, MinGW, and NonStop. +# +# (3) This script is generated from the Groovy template +# https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt +# within the Gradle project. +# +# You can find Gradle at https://github.com/gradle/gradle/. +# +############################################################################## + +# Attempt to set APP_HOME + +# Resolve links: $0 may be a link +app_path=$0 + +# Need this for daisy-chained symlinks. +while + APP_HOME=${app_path%"${app_path##*/}"} # leaves a trailing /; empty if no leading path + [ -h "$app_path" ] +do + ls=$( ls -ld "$app_path" ) + link=${ls#*' -> '} + case $link in #( + /*) app_path=$link ;; #( + *) app_path=$APP_HOME$link ;; + esac +done + +# This is normally unused +# shellcheck disable=SC2034 +APP_BASE_NAME=${0##*/} +# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036) +APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit + +# Use the maximum available, or set MAX_FD != -1 to use that value. +MAX_FD=maximum + +warn () { + echo "$*" +} >&2 + +die () { + echo + echo "$*" + echo + exit 1 +} >&2 + +# OS specific support (must be 'true' or 'false'). +cygwin=false +msys=false +darwin=false +nonstop=false +case "$( uname )" in #( + CYGWIN* ) cygwin=true ;; #( + Darwin* ) darwin=true ;; #( + MSYS* | MINGW* ) msys=true ;; #( + NONSTOP* ) nonstop=true ;; +esac + +CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar + + +# Determine the Java command to use to start the JVM. +if [ -n "$JAVA_HOME" ] ; then + if [ -x "$JAVA_HOME/jre/sh/java" ] ; then + # IBM's JDK on AIX uses strange locations for the executables + JAVACMD=$JAVA_HOME/jre/sh/java + else + JAVACMD=$JAVA_HOME/bin/java + fi + if [ ! -x "$JAVACMD" ] ; then + die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME + +Please set the JAVA_HOME variable in your environment to match the +location of your Java installation." + fi +else + JAVACMD=java + if ! command -v java >/dev/null 2>&1 + then + die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. + +Please set the JAVA_HOME variable in your environment to match the +location of your Java installation." + fi +fi + +# Increase the maximum file descriptors if we can. +if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then + case $MAX_FD in #( + max*) + # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked. + # shellcheck disable=SC2039,SC3045 + MAX_FD=$( ulimit -H -n ) || + warn "Could not query maximum file descriptor limit" + esac + case $MAX_FD in #( + '' | soft) :;; #( + *) + # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked. + # shellcheck disable=SC2039,SC3045 + ulimit -n "$MAX_FD" || + warn "Could not set maximum file descriptor limit to $MAX_FD" + esac +fi + +# Collect all arguments for the java command, stacking in reverse order: +# * args from the command line +# * the main class name +# * -classpath +# * -D...appname settings +# * --module-path (only if needed) +# * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables. + +# For Cygwin or MSYS, switch paths to Windows format before running java +if "$cygwin" || "$msys" ; then + APP_HOME=$( cygpath --path --mixed "$APP_HOME" ) + CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" ) + + JAVACMD=$( cygpath --unix "$JAVACMD" ) + + # Now convert the arguments - kludge to limit ourselves to /bin/sh + for arg do + if + case $arg in #( + -*) false ;; # don't mess with options #( + /?*) t=${arg#/} t=/${t%%/*} # looks like a POSIX filepath + [ -e "$t" ] ;; #( + *) false ;; + esac + then + arg=$( cygpath --path --ignore --mixed "$arg" ) + fi + # Roll the args list around exactly as many times as the number of + # args, so each arg winds up back in the position where it started, but + # possibly modified. + # + # NB: a `for` loop captures its iteration list before it begins, so + # changing the positional parameters here affects neither the number of + # iterations, nor the values presented in `arg`. + shift # remove old arg + set -- "$@" "$arg" # push replacement arg + done +fi + + +# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. +DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"' + +# Collect all arguments for the java command: +# * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments, +# and any embedded shellness will be escaped. +# * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be +# treated as '${Hostname}' itself on the command line. + +set -- \ + "-Dorg.gradle.appname=$APP_BASE_NAME" \ + -classpath "$CLASSPATH" \ + org.gradle.wrapper.GradleWrapperMain \ + "$@" + +# Stop when "xargs" is not available. +if ! command -v xargs >/dev/null 2>&1 +then + die "xargs is not available" +fi + +# Use "xargs" to parse quoted args. +# +# With -n1 it outputs one arg per line, with the quotes and backslashes removed. +# +# In Bash we could simply go: +# +# readarray ARGS < <( xargs -n1 <<<"$var" ) && +# set -- "${ARGS[@]}" "$@" +# +# but POSIX shell has neither arrays nor command substitution, so instead we +# post-process each arg (as a line of input to sed) to backslash-escape any +# character that might be a shell metacharacter, then use eval to reverse +# that process (while maintaining the separation between arguments), and wrap +# the whole thing up as a single "set" statement. +# +# This will of course break if any of these variables contains a newline or +# an unmatched quote. +# + +eval "set -- $( + printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" | + xargs -n1 | + sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' | + tr '\n' ' ' + )" '"$@"' + +exec "$JAVACMD" "$@" diff --git a/samples/weather-stdio-server/gradlew.bat b/samples/weather-stdio-server/gradlew.bat new file mode 100644 index 0000000..9d21a21 --- /dev/null +++ b/samples/weather-stdio-server/gradlew.bat @@ -0,0 +1,94 @@ +@rem +@rem Copyright 2015 the original author or authors. +@rem +@rem Licensed under the Apache License, Version 2.0 (the "License"); +@rem you may not use this file except in compliance with the License. +@rem You may obtain a copy of the License at +@rem +@rem https://www.apache.org/licenses/LICENSE-2.0 +@rem +@rem Unless required by applicable law or agreed to in writing, software +@rem distributed under the License is distributed on an "AS IS" BASIS, +@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +@rem See the License for the specific language governing permissions and +@rem limitations under the License. +@rem +@rem SPDX-License-Identifier: Apache-2.0 +@rem + +@if "%DEBUG%"=="" @echo off +@rem ########################################################################## +@rem +@rem Gradle startup script for Windows +@rem +@rem ########################################################################## + +@rem Set local scope for the variables with windows NT shell +if "%OS%"=="Windows_NT" setlocal + +set DIRNAME=%~dp0 +if "%DIRNAME%"=="" set DIRNAME=. +@rem This is normally unused +set APP_BASE_NAME=%~n0 +set APP_HOME=%DIRNAME% + +@rem Resolve any "." and ".." in APP_HOME to make it shorter. +for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi + +@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. +set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m" + +@rem Find java.exe +if defined JAVA_HOME goto findJavaFromJavaHome + +set JAVA_EXE=java.exe +%JAVA_EXE% -version >NUL 2>&1 +if %ERRORLEVEL% equ 0 goto execute + +echo. 1>&2 +echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2 +echo. 1>&2 +echo Please set the JAVA_HOME variable in your environment to match the 1>&2 +echo location of your Java installation. 1>&2 + +goto fail + +:findJavaFromJavaHome +set JAVA_HOME=%JAVA_HOME:"=% +set JAVA_EXE=%JAVA_HOME%/bin/java.exe + +if exist "%JAVA_EXE%" goto execute + +echo. 1>&2 +echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2 +echo. 1>&2 +echo Please set the JAVA_HOME variable in your environment to match the 1>&2 +echo location of your Java installation. 1>&2 + +goto fail + +:execute +@rem Setup the command line + +set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar + + +@rem Execute Gradle +"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %* + +:end +@rem End local scope for the variables with windows NT shell +if %ERRORLEVEL% equ 0 goto mainEnd + +:fail +rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of +rem the _cmd.exe /c_ return code! +set EXIT_CODE=%ERRORLEVEL% +if %EXIT_CODE% equ 0 set EXIT_CODE=1 +if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE% +exit /b %EXIT_CODE% + +:mainEnd +if "%OS%"=="Windows_NT" endlocal + +:omega diff --git a/samples/weather-stdio-server/settings.gradle.kts b/samples/weather-stdio-server/settings.gradle.kts new file mode 100644 index 0000000..015fa3f --- /dev/null +++ b/samples/weather-stdio-server/settings.gradle.kts @@ -0,0 +1,11 @@ +rootProject.name = "weather-stdio-server" + +plugins { + id("org.gradle.toolchains.foojay-resolver-convention") version "0.8.0" +} + +dependencyResolutionManagement { + repositories { + mavenCentral() + } +} diff --git a/samples/weather-stdio-server/src/main/kotlin/io/modelcontextprotocol/sample/server/McpWeatherServer.kt b/samples/weather-stdio-server/src/main/kotlin/io/modelcontextprotocol/sample/server/McpWeatherServer.kt new file mode 100644 index 0000000..9e26d23 --- /dev/null +++ b/samples/weather-stdio-server/src/main/kotlin/io/modelcontextprotocol/sample/server/McpWeatherServer.kt @@ -0,0 +1,132 @@ +package io.modelcontextprotocol.sample.server + +import io.ktor.client.* +import io.ktor.client.plugins.* +import io.ktor.client.plugins.contentnegotiation.* +import io.ktor.http.* +import io.ktor.serialization.kotlinx.json.* +import io.ktor.utils.io.streams.* +import io.modelcontextprotocol.kotlin.sdk.* +import io.modelcontextprotocol.kotlin.sdk.server.Server +import io.modelcontextprotocol.kotlin.sdk.server.ServerOptions +import io.modelcontextprotocol.kotlin.sdk.server.StdioServerTransport +import kotlinx.coroutines.CompletableDeferred +import kotlinx.coroutines.Job +import kotlinx.coroutines.runBlocking +import kotlinx.io.asSink +import kotlinx.io.buffered +import kotlinx.serialization.json.* + +// Main function to run the MCP server +fun `run mcp server`() { + val def = CompletableDeferred() + + // Base URL for the Weather API + val baseUrl = "https://api.weather.gov" + + // Create an HTTP client with a default request configuration and JSON content negotiation + val httpClient = HttpClient { + defaultRequest { + url(baseUrl) + headers { + append("Accept", "application/geo+json") + append("User-Agent", "WeatherApiClient/1.0") + } + contentType(ContentType.Application.Json) + } + // Install content negotiation plugin for JSON serialization/deserialization + install(ContentNegotiation) { + json(Json { + ignoreUnknownKeys = true + prettyPrint = true + }) + } + } + + // Create the MCP Server instance with a basic implementation + val server = Server( + Implementation( + name = "weather", // Tool name is "weather" + version = "1.0.0" // Version of the implementation + ), + ServerOptions( + capabilities = ServerCapabilities(tools = ServerCapabilities.Tools(listChanged = true)) + ) + ) { def.complete(Unit) } + + // Register a tool to fetch weather alerts by state + server.addTool( + name = "get_alerts", + description = """ + Get weather alerts for a US state. Input is Two-letter US state code (e.g. CA, NY) + """.trimIndent(), + inputSchema = Tool.Input( + properties = JsonObject( + mapOf( + "state" to JsonObject( + mapOf( + "type" to JsonPrimitive("string"), + "description" to JsonPrimitive("Two-letter US state code (e.g. CA, NY)") + ) + ), + ) + ), + required = listOf("state") + ) + ) { request -> + val state = request.arguments["state"]?.jsonPrimitive?.content + if (state == null) { + return@addTool CallToolResult( + content = listOf(TextContent("The 'state' parameter is required.")) + ) + } + + val alerts = httpClient.getAlerts(state) + + CallToolResult(content = alerts.map { TextContent(it) }) + } + + // Register a tool to fetch weather forecast by latitude and longitude + server.addTool( + name = "get_forecast", + description = """ + Get weather forecast for a specific latitude/longitude + """.trimIndent(), + inputSchema = Tool.Input( + properties = JsonObject( + mapOf( + "latitude" to JsonObject(mapOf("type" to JsonPrimitive("number"))), + "longitude" to JsonObject(mapOf("type" to JsonPrimitive("number"))), + ) + ), + required = listOf("latitude", "longitude") + ) + ) { request -> + val latitude = request.arguments["latitude"]?.jsonPrimitive?.doubleOrNull + val longitude = request.arguments["longitude"]?.jsonPrimitive?.doubleOrNull + if (latitude == null || longitude == null) { + return@addTool CallToolResult( + content = listOf(TextContent("The 'latitude' and 'longitude' parameters are required.")) + ) + } + + val forecast = httpClient.getForecast(latitude, longitude) + + CallToolResult(content = forecast.map { TextContent(it) }) + } + + // Create a transport using standard IO for server communication + val transport = StdioServerTransport( + System.`in`.asInput(), + System.out.asSink().buffered() + ) + + runBlocking { + server.connect(transport) + val done = Job() + server.onCloseCallback = { + done.complete() + } + done.join() + } +} diff --git a/samples/weather-stdio-server/src/main/kotlin/io/modelcontextprotocol/sample/server/WeatherApi.kt b/samples/weather-stdio-server/src/main/kotlin/io/modelcontextprotocol/sample/server/WeatherApi.kt new file mode 100644 index 0000000..671186c --- /dev/null +++ b/samples/weather-stdio-server/src/main/kotlin/io/modelcontextprotocol/sample/server/WeatherApi.kt @@ -0,0 +1,91 @@ +package io.modelcontextprotocol.sample.server + +import io.ktor.client.HttpClient +import io.ktor.client.call.body +import io.ktor.client.request.get +import kotlinx.serialization.Serializable +import kotlinx.serialization.json.JsonObject + +// Extension function to fetch forecast information for given latitude and longitude +suspend fun HttpClient.getForecast(latitude: Double, longitude: Double): List { + // Build the URI using provided latitude and longitude + val uri = "/points/$latitude,$longitude" + // Request the points data from the API + val points = this.get(uri).body() + + // Request the forecast using the URL provided in the points response + val forecast = this.get(points.properties.forecast).body() + + // Map each forecast period to a formatted string + return forecast.properties.periods.map { period -> + """ + ${period.name}: + Temperature: ${period.temperature} ${period.temperatureUnit} + Wind: ${period.windSpeed} ${period.windDirection} + Forecast: ${period.detailedForecast} + """.trimIndent() + } +} + +// Extension function to fetch weather alerts for a given state +suspend fun HttpClient.getAlerts(state: String): List { + // Build the URI using the given state code + val uri = "/alerts/active/area/$state" + // Request the alerts data from the API + val alerts = this.get(uri).body() + + // Map each alert feature to a formatted string + return alerts.features.map { feature -> + """ + Event: ${feature.properties.event} + Area: ${feature.properties.areaDesc} + Severity: ${feature.properties.severity} + Description: ${feature.properties.description} + Instruction: ${feature.properties.instruction} + """.trimIndent() + } +} + +// Data class representing the points response from the API +@Serializable +data class Points( + val properties: Properties +) { + @Serializable + data class Properties(val forecast: String) +} + +// Data class representing the forecast response from the API +@Serializable +data class Forecast( + val properties: Properties +) { + @Serializable + data class Properties(val periods: List) + + @Serializable + data class Period( + val number: Int, val name: String, val startTime: String, val endTime: String, + val isDaytime: Boolean, val temperature: Int, val temperatureUnit: String, + val temperatureTrend: String, val probabilityOfPrecipitation: JsonObject, + val windSpeed: String, val windDirection: String, + val shortForecast: String, val detailedForecast: String, + ) +} + +// Data class representing the alerts response from the API +@Serializable +data class Alert( + val features: List +) { + @Serializable + data class Feature( + val properties: Properties + ) + + @Serializable + data class Properties( + val event: String, val areaDesc: String, val severity: String, + val description: String, val instruction: String?, + ) +} diff --git a/samples/weather-stdio-server/src/main/kotlin/io/modelcontextprotocol/sample/server/main.kt b/samples/weather-stdio-server/src/main/kotlin/io/modelcontextprotocol/sample/server/main.kt new file mode 100644 index 0000000..21100dd --- /dev/null +++ b/samples/weather-stdio-server/src/main/kotlin/io/modelcontextprotocol/sample/server/main.kt @@ -0,0 +1,3 @@ +package io.modelcontextprotocol.sample.server + +fun main() = `run mcp server`() \ No newline at end of file diff --git a/samples/weather-stdio-server/src/test/kotlin/io/modelcontextprotocol/sample/client/ClientStdio.kt b/samples/weather-stdio-server/src/test/kotlin/io/modelcontextprotocol/sample/client/ClientStdio.kt new file mode 100644 index 0000000..20c2a79 --- /dev/null +++ b/samples/weather-stdio-server/src/test/kotlin/io/modelcontextprotocol/sample/client/ClientStdio.kt @@ -0,0 +1,56 @@ +package io.modelcontextprotocol.sample.client + +import io.modelcontextprotocol.kotlin.sdk.CallToolRequest +import io.modelcontextprotocol.kotlin.sdk.Implementation +import io.modelcontextprotocol.kotlin.sdk.TextContent +import io.modelcontextprotocol.kotlin.sdk.client.Client +import io.modelcontextprotocol.kotlin.sdk.client.StdioClientTransport +import kotlinx.coroutines.runBlocking +import kotlinx.io.asSink +import kotlinx.io.asSource +import kotlinx.io.buffered +import kotlinx.serialization.json.JsonObject +import kotlinx.serialization.json.JsonPrimitive + + +fun main(): Unit = runBlocking { + val process = ProcessBuilder("java", "-jar", "build/libs/weather-stdio-server-0.1.0-all.jar") + .start() + + val transport = StdioClientTransport( + input = process.inputStream.asSource().buffered(), + output = process.outputStream.asSink().buffered() + ) + + // Initialize the MCP client with client information + val client = Client( + clientInfo = Implementation(name = "weather", version = "1.0.0"), + ) + + client.connect(transport) + + + val toolsList = client.listTools()?.tools?.map { it.name } + println("Available Tools = $toolsList") + + val weatherForecastResult = client.callTool( + CallToolRequest( + name = "get_forecast", + arguments = JsonObject(mapOf("latitude" to JsonPrimitive(38.5816), "longitude" to JsonPrimitive(-121.4944))) + ) + )?.content?.map { if (it is TextContent) it.text else it.toString() } + + println("Weather Forcast: ${weatherForecastResult?.joinToString(separator = "\n", prefix = "\n", postfix = "\n")}") + + val alertResult = + client.callTool( + CallToolRequest( + name = "get_alerts", + arguments = JsonObject(mapOf("state" to JsonPrimitive("TX"))) + ) + )?.content?.map { if (it is TextContent) it.text else it.toString() } + + println("Alert Response = $alertResult") + + client.close() +} \ No newline at end of file